Growing & Winemaking


A Pump for Every Purpose

January 2010
by Paul Franson

While winemakers rarely show off their pumps to visitors as they do barrels and sorting tables, conscientious cellar masters recognize pumps’ important roles in maintaining wine quality. Today they are choosing them with greater care, and from a wider range of pumping technology.

And while pumps might seem like trivial equipment among the destemmers, sorting tables, presses and tanks at boutique wineries, they can represent significant expenses, costing as much as $30,000.

The importance of choosing the proper pump stems from the need to treat must and wine gently, especially when it contains whole or crushed berries and their vulnerable seeds. (See the article on seed tannins on page 46.) Smashing and crushing the berries and seeds can release unwanted compounds into the stream, creating off flavors and problems with clarification. Additionally, the wrong pump can introduce unwanted oxygen into the wine and emulsify it with solids.

Old wineries—and, increasingly, new ones—attempt to minimize pumping by taking advantage of gravity and/or the trusty forklift, but it’s not usually practical to eliminate all pumping. Boutique wineries, in particular, tend to prioritize transferring their wine as delicately as possible.

Many types of pumps are used in winemaking, but only a few can transfer must and wine delicately with low rates of oxygen pickup. Fortunately, suppliers offer gentle alternatives that have been designed transferring delicate products like high-quality grape must and wine.

Peristaltic pumps
The peristaltic pump is becoming increasingly popular for must and wine transfer. Examples include the Enoveneta PEV sold by Criveller, CME pumps sold by P&L Specialties, CMA pumps supplied by AWS Prospero and Della Toffola peristaltic pumps.

A peristaltic pump is deceptively simple in operation. This type of pump consists of a U-shaped flexible tube around a rotor with rollers that simply push the wine or must forward as if they are squeezing toothpaste from a tube—but continuously. There is no contact between the wine and the mechanical parts. All parts of peristaltic pumps in contact with the product are made of inert stainless steel and food-grade rubber.

Peristaltic pumps aren’t new to the wine industry, but they have been gaining popularity of late. They provide very delicate transfer of wine and are self-priming. They do not turn at high revolutions (which tend to beat or crush must), do not introduce oxygen and can be used to transfer solids and liquids.

They also can provide reversible flow, precise control of product transfer and can be run dry without damage. These pumps can transfer from 1 to 40 tons of liquid or liquids and solids per hour.

They’re considered relatively expensive, however, costing from $10,000 to more than $30,000 for very large units. The CMA pumps are available in three sizes, priced from $13,000 to $18,500. Ed Barr, president of P&L, says the pumps are about 30% more expensive than conventional pumps like the popular Carlsen Waukesha pumps. Peristaltic pumps are also relatively large and heavy.

Some winemakers have expressed concern that the rubber tube might be too delicate and require frequent replacement. Barr says that while the company supplies a spare tube with each pump, he has only sold one additional tube in the six years the company has been selling the pumps. He adds that some of his customers pump for 400 feet through 3- to 6-inch lines at flow rates of 2.5 gpm to 260 gpm. “They can run all day. It won’t hurt them,” Barr says.

Accessories make the pumps even more versatile. One popular accessory is a hopper with a feed screw that permits the pump to be used under a destemmer. Another accessory is used for filling barrels with an automatic shut-off when the barrel is filled to the correct height.

The peristaltic pump can be used in almost all winery pumping applications, but Criveller enologist and sales representative Davide Criveller says it is not suitable for filtering and/or bottling. He adds that Enoveneta PEV peristaltic pumps are currently the most popular pumps the company sells to boutique wineries.

Volumetric pumps
Volumetric pumps are used primarily for crushed grapes and not liquid. Criveller sells the Enoveneta EVP volumetric pump, and Davide Criveller claims the pumps use the most delicate transfer methods designed specifically for transferring whole clusters. These pumps use a specially designed lobe that “scoops” up the grapes and clusters. He says this is “by far the most delicate way of transferring whole clusters, crushed grapes and pressed grapes.”

Criveller says it is the best way to transfer high-quality whole berries from a destemmer/crusher to a tank. These pumps can range in speed from about 3 to 22 tons per hour and cost $8,000-$11,000.

One of the newer innovations Criveller sells from its Ontario location is the self-priming Francesca pump, which has a very delicate transfer method suitable for moving any type of liquid or mixture including crushed and pressed grapes. The manufacturer calls the new type of design a rotary piston pump. These pumps can achieve high pressures with low revolutions, the ideal environment for product transfer.

The design encompasses two independent, modified lobes (not to be confused with lobe pumps), which turn at different rotational speeds. The two lobes work in conjunction: one to “pull” the product into the pump cavity, the other to “push” it out. This pump has an optional wireless remote control. Francesca pumps range in speed from about 400 to 15,000 gallons per hour and cost $13,000-$27,500. 

Lobe pumps are a standard in the industry and are excellent for transferring wine, filtering and bottling. They can operate at low revolutions, yet produce high pressure with very low oxygen pick-up.

Criveller discourages the use of lobe pumps for transporting grapes, however, because the lobes act like gears. If berries enter the pump cavity and the lobes rotate towards one another, they tend to crush seeds and shred berries, which can release harsh polyphenolics from skins and seeds.

Apart from grape processing, the lobe pump is an excellent choice for most other liquid transfer applications. Criveller’s lobe pumps range in speeds from about 1,800 to 6,100 gallons per hour, and cost between $7,500 and $10,000.

Seepex makes progressive cavity pumps for portable and stationary use in the wine industry and claims that their gentle, reduced pulsation pumping of grapes makes them suitable for transferring berries, must and even pomace.

These pumps gently convey thin and high viscosity products, with or without solids, as well as cold or high temperature products without pulsation and with minimal shear. Seepex offers custom-designed pumps for wineries as well as other applications.

Their internally streamlined pump housings are easy to clean, leaving virtually no residual matter inside, and comply with high hygienic standards. The BT-range pumps have a hopper and a feed screw for conveying highly viscous media and those containing solids such as whole grape must. The length of the hopper opening can be adjusted to the conditions of use. All the wine pumps use elastomers that meet FDA requirements. The Seepex pumps have capacities from 19 to 396 gpm.

Della Toffola makes centrifugal pumps with impellers in rubber or steel, and also volumetric pumps. The main difference between the two groups is that centrifugal pumps are distinguished by elevated rotation speed and correspondingly more energetic action on the product, while positive displacement pumps rotate more slowly and give the product much more delicate treatment.

Although centrifugal pumps with rubber or steel impellers are widely used in the winemaking sector, Della Toffola says the pumps now in highest demand are Mohno pumps (a type of pump originated by Mohno, not to be confused with Moyno Inc.), peristaltic pumps, piston pumps and lobed pumps. Della Toffola has dedicated the greatest attention to the latter group.

A Mohno pump is one-rotor screw pump. They can be supplied with hoppers to transfer large amounts of solids like crushed grape, marc (pomace) or whole grapes that require constant, even flow, with maximum delicacy. Some are designed for transporting must rather than slurries of berries.

In order to ensure this result, the pumps rotate at low rpm and mount a hollow shaft rotor that permits operation without vibration and with less friction, to the advantage of product quality. Standard-built entirely in AISI 304 stainless steel, they also feature an anti-dry running device that prevents operation when no product is present.

Moyno Inc. offers progressing cavity pumps, which feature an open-throat hopper design with an auger for positive product feed when handling semi-dry or high solids content mixtures.

It features a crown gear-type universal joint, which Moyno claims is the heaviest-duty drive train configuration available in the industry. It is capable of accommodating high torsional and thrust loads. Patented joint seals protect the gear joints from contamination. The Moyno pump offers flow rates to 400 gpm, and pressure capabilities to 350 psi.

Della Toffola provides two-cylinder stainless steel piston pumps that offer elevated output and smooth, balanced flow without shaking, even with hard-to-process liquids. They are suggested for transferring wines or must with the greatest respect of product quality.

Wilden pumps says its Saniflo Hygienic series air-operated double diaphragm pumps were designed to meet strict guidelines for sanitation in wine production. They include higher surface polishes and have no crevices or dead legs to eliminate unwanted microbial activity. Typical applications include general transfer, pumpover processes, blending, barrel feeding/topping, filter feed, lees handling and filler feed. Saniflo pumps also feature standard self-priming, dry-running, deadhead capability, low shear transfer and portability.

Some pumps declining in popularity
David Criveller says his company has been selling fewer centrifugal pumps in recent years. They can transfer a high amount of liquid in a short period of time, but are known to pick up oxygen, are not self-priming and operate at very high revolutions per minute. He also regards piston pumps as “a thing of the past. The pumps are built like tanks: very large and extremely heavy.”

Views from winemakers
Antica Napa Valley, which is owned by the innovative Antinori family of Tuscany, recently installed a large CMA peristaltic pump from Prospero. Winemaker Nate Weis received the pump during the summer, so this harvest was its first use. “We got it because tannins can be a problem for us, and we do very little crushing. We understand that the peristaltic pump minimizes damage to the berries,” Weis says. It’s a little early to judge, but he says the tannin management seemed very effective this year.

Weis hasn’t used the pump for other applications yet, and the winery also has a number of the “ubiquitous” Carlsen Waukesha pumps, a Yamaha MDP50 diaphragm pump used for racking barrels, and some old pumps from the winery’s early days a decade ago.

In Santa Maria, Calif., Ken Volk Winery occupies the former Byron space. It produces about 18,000 to 20,000 cases per year. Owner/winemaker Ken Volk, former proprietor of Wild Horse Winery in Paso Robles, says he’s worked with every type of pump during his long career, but he now uses a peristaltic pump to transfer must to fermenters. “It pumps the fruit more consistently than other pumps I’ve used, with minimal shear,” he says.

He acquired a large pump manufactured by CME that is rated at 360 gallons per minute, but also operates it at lower speeds.

Volk has used a Carlsen worm with Waukesha pump with 3-inch feed and says it worked well. “It has incredible suction, but it’s not as good at pumping dry fruit, which we get here.” He adds that it’s very versatile, and he now uses it for filtering, with a fitting to reduce pressure. “If I had to get by with one pump,” he admits, “it would be the Waukesha.”

Volk also uses air diaphragm pumps for transferring liquid. He likes that he can shut the valve on the output without damage. “It’s gentle,” he says, “but not as robust as the Waukesha.” The only centrifugal pumps he uses are for glycol for cooling.

Another operation using a peristaltic pump is Paul Hobbs’ second winery, Crossbarn, in Sebastopol, Calif. Winemaker Jason Valenti says Hobbs’ main winery uses gravity feed with a crane, but it wasn’t practical at the new winery. The winery acquired an Enoveneta peristaltic pump in an attempt to mimic the gentle gravity feed, and he uses it only to transfer must at this point. Valenti says, “We were looking for the gentlest pump we could find, and from my conversations and research, the peristaltic pump fit that bill.

“It works wonderfully,” Valenti says. “It’s generally proven ideal for moving the whole berries, and it’s powerful and reliable.” He also uses air pumps for filling barrels.

So, far from being a static, boring subject, pumps are undergoing innovation and improvement like other equipment used in winemaking. Winemakers seeking highest quality are finding new types of pumps that handle their grapes and wine more gently than ever. They provide the closest practical alternative to gravity feed available for most winemakers.

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